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Knee Giving Way

More than 10% of the adult population report having experienced their knee ‘giving way’ or buckling at least once in their life. This happens to people of all ages, fitness, and health levels.

Knee buckling is almost always associated with knee pain and muscle buckling, which, when left untreated can have a debilitating impact on quality of life. (1)

What happens when your knee is giving way?

When y our knee buckles or gives way, it’s often characterised by a sudden loss of postural support due to knee instability, especially during weight-bearing activities. It is commonly associated with disorders like osteoarthritis and Knee pain. (2)

It’s commonly associated with injuries of the anterior cruciate ligaments but this isn’t always a prerequisite for knee buckling. It may also occur in individuals with no history of an injury or a diagnosis of connective tissue disorders.

Common features that are seen in conjunction with Knee Buckling include weakness of the quadriceps, limitations in performing physical activity, and radiographic findings of knee osteoarthritis. (3)

How Do The Knees Work?

The knees are classified as hinge joints that help connect the different bones of the legs. The bones which are connected by the knee joint include the thigh bone known as Femur and the lower leg bone known as Tibia. As a result, the knees allow movement mainly in one plane, which is also known as Flexion and Extension of the legs. In addition, the stabilization of the knee joint is allowed by the presence of ligaments and cartilage pads known as menisci. The major ligaments that play an active role in the knee joint include:

  • Collateral Ligaments: Collateral Ligaments include the medial collateral ligaments and the lateral collateral ligament. They are located on both sides of the knees and limit the sideways bending movements.
  • Anterior Cruciate Ligament: Anterior Cruciate Ligament is located along the middle portion of the Knee joint and helps connect the thigh bone to the shinbone. It limits the forward movement of the shin bone and rotational movement of the leg.
  • Posterior Cruciate Ligament: posterior Cruciate Ligaments limit the backward movement of the shinbone and help connect the thigh bone to the top of the shin bone. You might find this useful: Knee pain location chart (4)

Common Causes of Your Knee Giving Way

Knee buckling is a complex condition and the causes can vary depending on the patient. While a majority of individuals associated knee buckling with osteoarthritis, it may not be the only cause for this condition. Studies have shown that more than 50% of individuals with Knee Buckling may not have signs of arthritis as seen on X-rays. (5)

The knee joint has a complex structure, which is what makes the analysis of the cause of  Knee Buckling difficult. When any of these parts get damaged, either due to an injury or a connective tissue disorder that alters its function, it may result in instability, and the individual may experience knee buckling.

The conditions which are found to have a causative relationship with Knee Buckling include Ligament Tears, Meniscal Tear, Femoral Nerve Damage, Plica Syndrome, Knee arthritis, Multiple Sclerosis, and Patella Dislocation.

Ligament tear as a cause of your knee giving way

Ligament injuries and tears, which may be partial or complete, can lead to knee instability and knee giving way. The most common types of ligaments tears responsible for this include:

  • Tear in the Anterior Cruciate Ligament: Anterior Cruciate Ligament Tear might occur due to sudden changes in movement and direction of motion – as may be seen during sports. This may be accompanied by a pop sound, particularly as an individual suddenly changes their direction or falls after being unstable. ACL tear is often accompanied by pain and swelling. (6)
  • Tear in the Posterior Cruciate Ligament: PCL most commonly occurs as an individual falls directly on the front of the knee. However, such a situation may develop when the shin is hit directly from the front, as may be seen during a road traffic accident.
  • Tear in the Medial Collateral Ligament: Tear in the MCL occurs when the outside of the knee gets a direct hit. When this hit leads to knee instability and knee-buckling, it is usually indicative of a significant tear in the Medial Collateral Ligament.
  • Tear in the Lateral Collateral Ligament: Lateral Collateral Ligament tears are associated with a painful sensation outside the knee joint and may occur in conjunction with other injuries.

Meniscal Tear

A meniscus tear is common cause for the knee giving way. This could be down to a movement that involves sudden twisting, turning, and pivoting. Meniscal tears are more common in people over the age of 30, as this is generally when the menisci start to weaken. Meniscal tears are usually identified by pain, stiffness, swelling, feeling of knee lock, popping, and movement difficulties. (7)

Femoral nerve damage

The femoral nerve is a major nerve responsible for proving sensations to the lower leg. Damage to this nerve leads to weakness of the knees, which makes them more prone to buckling. Common symptoms of femoral nerve damage include tingling, burning, pain, and numbness.

Conditions that can increase the risk of femoral nerve damage include metabolic disorders like diabetes, arthritis, use of certain medications, alcohol consumption, fibromyalgia, and knee injuries. Femora nerve damage may be treated according to the cause and factors responsible for it. It may include surgical procedures, physiotherapy, pain medication, and making lifestyle changes. Some of these treatments may not be able to treat the condition, but they may help manage the symptoms and prevent them from getting worse. (8)

Syndrome of Plica

The inflammation causes the syndrome of Plica in the fold found in the middle of the knee joint membrane. This is known as Medial Plica, and its inflammation ultimately leads to buckling of the knees. This may also be associated with pain on the inside of the knees, clicking sounds on movement, and tenderness of the knee cap.

Plica Syndrome is most commonly caused by overuse of knees or a knee injury. The recommended treatment for this condition is physical therapy, which may help in strengthening the muscles supporting the knee joint. Some individuals may also be given a corticosteroid injection to control the level of inflammation and provide symptomatic relief. Very rarely is surgery recommended for the removal of the Plica. (9)

Knee Arthritis

Arthritis is a condition involving inflammation of the joint, which may worsen over time. There are different forms so arthritis affecting the knee, like rheumatoid arthritis and osteoarthritis, and both of these may lead to significant Knee buckling. While osteoarthritis usually affects only one knee, rheumatoid arthritis may occur in both knees. The symptoms which may be associated with arthritis include stiffness of the knees, pain in movement, locking sensation, and clicking and grinding sounds. (10)

The recommendations for the management of arthritis generally include inflammatory medications, physiotherapy, corticosteroid injections under a doctor’s supervision, and wearing assistive devices like a knee brace.

Multiple Sclerosis as a cause of your knee giving way

The knee giving way has even been reported as a symptom of Multiple Sclerosis. This is a condition that causes the body’s immune system to attack the protective covering over the nerves, which may also affect their conduction potential. Those suffering with Multiple sclerosis report weakness and numbness of the legs along with knee-buckling; however, the exact cause for this is still under investigation. The common symptoms associated with Multiple Sclerosis other than knee-buckling include dizziness, excessive fatigue, tiredness, loss of vision, and tremors. Since there is currently no cure for Multiple Sclerosis, it may be managed by injecting the patients with a corticosteroid which helps control the inflammation in the nerves. (11)

Patella Dislocation

Patella, which is also known as the knee cap, is an essential component of the Knee joint. A dislocation of the patella, which a direct blow to the knee may cause, can lead to significant knee instability. Therefore, it may also be referred to as patellar instability.

There are two types of Patellar instabilities based on the extent of dislocation. While Patellar Dislocation is when the knee cap is completely out of the joint groove, patellar Subluxation involves a partial movement of the kneecap outside the groove.

How Can Knee Buckling Be Diagnosed?

The diagnosis of Knee Buckling generally involves an initial physical exam, which diagnostic radiographs may follow.

Physical Examination

A health professional may start the physical examination by looking for clear causative signs of knee-buckling. These can include visible bruising, tenderness around the knee, crepitus on the movement of the knee, deformity of any structure, and limited range of motion.

Then, to look for any meniscal tears and damage to the ligaments, a detailed test may also be conducted, including the McMurray test, Ege’s test, and Lachman test. While the knee may be rotated to look for any tears in the McMurray test, Ege’s test involves the patient assuming a squatting position as the doctor feels for a click. Lachman tests are similar, but the doctors themselves bend the knee while the patient is lying down.

Diagnostic Imaging

Imaging studies may follow physical examination in order to evaluate the site in more detail. The type of imaging used depends on the patient factors and the suspected problem. For example, X Rays are most commonly recommended for the evaluation of dislocations across the knee, while MRIs may be more appropriate for studying ligament and cartilage injuries.

Treatment for people who’s knee is giving way

The treatment options that are currently recommended for the management of Knee Buckling include:

  • NSAIDs: NSAIDs stands for non-steroidal anti-inflammatory drugs, which include drugs like aspirin, naproxen sodium, and ibuprofen. These are recommended for inflammatory conditions affecting the body, like arthritis, which is a common cause of knee buckling. These may be accompanied by prescription pain medication if the patient is in severe pain. However, it is important to consume prescription medication according to medical advice. (12)
  • Rest, Ice, Compression, Elevation: The RICE method is often recommended by specialists for the home treatment of minor injuries. As the name suggests, this method involves resting the injured knee, application of ice from time to time, wrapping it using a soft dressing, and keeping the leg elevated.
  • Ultrasound Therapy: Ultrasound therapy may be conducted by trained specialists for the management of knee buckling. It may be given in combination with steroids and helps by reducing the total inflammatory activity and pain.
  • Physical Therapy: Physical Therapy is an effective way to manage knee instability and knee-buckling. It works by allowing the strengthening of muscles around the knees, which helps build endurance, balance, coordination, and overall improvement in knee conditions.
  • Knee Cap Reduction: If a displaced knee cap causes the knee-buckling due to a previous injury, it may be manipulated by a healthcare professional like doctor or physiotherapist back to its original place. (13)
  • Support Braces and Bandages: The doctor may also recommend the use of support braces, bandages and physiotherapy tapes, as these allow better healing of the injured area by taking pressure off the sprain. Support bandages also allow the individuals to maintain mobility of the injured knee, so the surrounding muscles can be strengthened.
  • Knee Surgery: Individuals with moderate to severely unstable knees may require the consultation of an orthopedic surgeon, who can evaluate if the surgical procedure of the knee may be a better option for them. Knee surgery may include repair of damaged tendons, ligaments and realignment of the knee cap. (14)


Structures in the knee that can cause it to give way have a poor blood supply, which is why they can struggle to heal on their own. It is the oxygen and nutrients in our blood supply that helps to heal and strengthen these structures.

Prolotherapy involves the injection of a regenerative solution into these structures to provide a direct supply of what is required to heal and repair.

As the treatment is helping to treat the root cause of the problem, it is deemed to be a permanent fix.

Can Knee Instability Be Prevented?

The practices that one may follow to improve the balance and stability of their knees and surrounding structure include:

  • Regular exercises: Exercises involving toe raises and squats are targeted towards strengthening the Anterior Cruciate Ligament, which is an essential part of the knee joint.
  • Using a Seat Belt in the Car: A common cause of Knee instability and buckling is direct trauma to the knee during a road traffic accident. Wearing a seat belt can protect the individual from a dashboard-associated knee injury.
  • Prevent Overuse Knee Injury: Knee overuse injury is another cause of knee-buckling and may be prevented by warming up before a workout and gradually increasing its time and intensity.


  1. Felson, D. T., Niu, J., McClennan, C., Sack, B., Aliabadi, P., Hunter, D. J., Guermazi, A., & Englund, M. (2007). Knee buckling: prevalence, risk factors, and associated limitations in function. Annals of internal medicine, 147(8), 534–540. https://doi.org/10.7326/0003-4819-147-8-200710160-00005
  2. Fitzgerald, G. K., Piva, S. R., & Irrgang, J. J. (2004). Reports of joint instability in knee osteoarthritis: its prevalence and relationship to physical function. Arthritis and rheumatism, 51(6), 941–946. https://doi.org/10.1002/art.20825
  3. Knoop, J., van der Leeden, M., van der Esch, M., Thorstensson, C. A., Gerritsen, M., Voorneman, R. E., Lems, W. F., Roorda, L. D., Dekker, J., & Steultjens, M. P. (2012). Association of lower muscle strength with self-reported knee instability in osteoarthritis of the knee: results from the Amsterdam Osteoarthritis cohort. Arthritis care & research, 64(1), 38–45. https://doi.org/10.1002/acr.20597
  4. org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. How does the knee work? 2020 Aug 13. Available from: https://www.ncbi.nlm.nih.gov/books/NBK561512/
  5. David T. Felson, Jingbo Niu, Christine McClennan, et al. Knee Buckling: Prevalence, Risk Factors, and Associated Limitations in Function. Ann Intern Med.2007;147:534-540. [Epub 16 October 2007].doi:7326/0003-4819-147-8-200710160-00005
  6. Evans J, Nielson Jl. Anterior Cruciate Ligament Knee Injuries. [Updated 2022 Feb 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499848/
  7. Raj MA, Bubnis MA. Knee Meniscal Tears. [Updated 2021 Jul 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK431067/
  8. Hsu H, Siwiec RM. Knee Osteoarthritis. [Updated 2021 Jul 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK507884/
  9. Refai NA, Tadi P. Anatomy, Bony Pelvis and Lower Limb, Thigh Femoral Nerve. [Updated 2021 Oct 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK556065/
  10. Casadei K, Kiel J. Plica Syndrome. [Updated 2021 Jul 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK535362/
  11. Güner, Senem et al. “Knee muscle strength in multiple sclerosis: relationship with gait characteristics.” Journal of physical therapy science vol. 27,3 (2015): 809-13. doi:10.1589/jpts.27.809
  12. Felson DT. Developments in the clinical understanding of osteoarthritis. Arthritis Res Ther. 2009;11(1):203. doi:10.1186/ar2531
  13. Hayat Z, El Bitar Y, Case JL. Patella Dislocation. [Updated 2021 Jul 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538288/
  14. Fithian, D. C., Paxton, E. W., & Cohen, A. B. (2004). Indications in the treatment of patellar instability. The journal of knee surgery, 17(1), 47–56. https://doi.org/10.1055/s-0030-1247149
  15. Zlotnicki JP, Naendrup JH, Ferrer GA, Debski RE. Basic biomechanic principles of knee instability. Curr Rev Musculoskelet Med. 2016;9(2):114-122. doi:10.1007/s12178-016-9329-8

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